1. Field of the Invention
The present invention relates generally to air conditioning systems for use in vehicles, vehicles comprising such air conditioning systems, methods for driving a hybrid compressor of such air conditioning systems. In particular, the present invention is directed towards vehicles, air conditioning systems, and methods for driving a hybrid compressor, in which a drive source of the hybrid compressor switches from an electric drive motor of the hybrid compressor to an engine of the vehicle, when predetermined conditions are satisfied.
2. Description of Related Art
Known hybrid vehicles include a first drive source, e.g., an engine, and an air conditioning system. Such known air conditioning systems, such as the air conditioning system described in U.S. Pat. No. 5,867,996, include a hybrid compressor, and the hybrid compressor includes a second drive source, e.g., an electric motor, and an electrical power supply, e.g., a battery, for the second drive source. The hybrid compressor may be driven by the first drive source or the second drive source, or both. Specifically, the first drive source drives the hybrid compressor when the first drive source is engaged, and the second, drive source drives the hybrid compressor when the first drive source is disengaged. As such, whether the first drive source or the second drive source drives the hybrid compressor depends on whether the first drive source is engaged or disengaged. Nevertheless, when the voltage of the electrical power supply is less than a predetermined voltage, or when the amount of power consumed by the second drive source is greater than a predetermined amount of power, the ability of the air conditioning system to deliver sufficiently cooled air or sufficiently heated air to an interior of the vehicle is reduced. Moreover, the driving force of the second drive source may be insufficient to drive other components of the air conditioning system, e.g., a blower.